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mac80211: minstrel_ht: do not always skip ht rates vht_only is true
[deliverable/linux.git] / net / mac80211 / rc80211_minstrel_ht.c
1 /*
2 * Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8 #include <linux/netdevice.h>
9 #include <linux/types.h>
10 #include <linux/skbuff.h>
11 #include <linux/debugfs.h>
12 #include <linux/random.h>
13 #include <linux/moduleparam.h>
14 #include <linux/ieee80211.h>
15 #include <net/mac80211.h>
16 #include "rate.h"
17 #include "rc80211_minstrel.h"
18 #include "rc80211_minstrel_ht.h"
19
20 #define AVG_PKT_SIZE 1200
21
22 /* Number of bits for an average sized packet */
23 #define MCS_NBITS (AVG_PKT_SIZE << 3)
24
25 /* Number of symbols for a packet with (bps) bits per symbol */
26 #define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps))
27
28 /* Transmission time (nanoseconds) for a packet containing (syms) symbols */
29 #define MCS_SYMBOL_TIME(sgi, syms) \
30 (sgi ? \
31 ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \
32 ((syms) * 1000) << 2 /* syms * 4 us */ \
33 )
34
35 /* Transmit duration for the raw data part of an average sized packet */
36 #define MCS_DURATION(streams, sgi, bps) MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps)))
37
38 #define BW_20 0
39 #define BW_40 1
40 #define BW_80 2
41
42 /*
43 * Define group sort order: HT40 -> SGI -> #streams
44 */
45 #define GROUP_IDX(_streams, _sgi, _ht40) \
46 MINSTREL_HT_GROUP_0 + \
47 MINSTREL_MAX_STREAMS * 2 * _ht40 + \
48 MINSTREL_MAX_STREAMS * _sgi + \
49 _streams - 1
50
51 /* MCS rate information for an MCS group */
52 #define MCS_GROUP(_streams, _sgi, _ht40) \
53 [GROUP_IDX(_streams, _sgi, _ht40)] = { \
54 .streams = _streams, \
55 .flags = \
56 IEEE80211_TX_RC_MCS | \
57 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
58 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
59 .duration = { \
60 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26), \
61 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52), \
62 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78), \
63 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104), \
64 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156), \
65 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208), \
66 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234), \
67 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) \
68 } \
69 }
70
71 #define VHT_GROUP_IDX(_streams, _sgi, _bw) \
72 (MINSTREL_VHT_GROUP_0 + \
73 MINSTREL_MAX_STREAMS * 2 * (_bw) + \
74 MINSTREL_MAX_STREAMS * (_sgi) + \
75 (_streams) - 1)
76
77 #define BW2VBPS(_bw, r3, r2, r1) \
78 (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1)
79
80 #define VHT_GROUP(_streams, _sgi, _bw) \
81 [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \
82 .streams = _streams, \
83 .flags = \
84 IEEE80211_TX_RC_VHT_MCS | \
85 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
86 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \
87 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
88 .duration = { \
89 MCS_DURATION(_streams, _sgi, \
90 BW2VBPS(_bw, 117, 54, 26)), \
91 MCS_DURATION(_streams, _sgi, \
92 BW2VBPS(_bw, 234, 108, 52)), \
93 MCS_DURATION(_streams, _sgi, \
94 BW2VBPS(_bw, 351, 162, 78)), \
95 MCS_DURATION(_streams, _sgi, \
96 BW2VBPS(_bw, 468, 216, 104)), \
97 MCS_DURATION(_streams, _sgi, \
98 BW2VBPS(_bw, 702, 324, 156)), \
99 MCS_DURATION(_streams, _sgi, \
100 BW2VBPS(_bw, 936, 432, 208)), \
101 MCS_DURATION(_streams, _sgi, \
102 BW2VBPS(_bw, 1053, 486, 234)), \
103 MCS_DURATION(_streams, _sgi, \
104 BW2VBPS(_bw, 1170, 540, 260)), \
105 MCS_DURATION(_streams, _sgi, \
106 BW2VBPS(_bw, 1404, 648, 312)), \
107 MCS_DURATION(_streams, _sgi, \
108 BW2VBPS(_bw, 1560, 720, 346)) \
109 } \
110 }
111
112 #define CCK_DURATION(_bitrate, _short, _len) \
113 (1000 * (10 /* SIFS */ + \
114 (_short ? 72 + 24 : 144 + 48) + \
115 (8 * (_len + 4) * 10) / (_bitrate)))
116
117 #define CCK_ACK_DURATION(_bitrate, _short) \
118 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \
119 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE))
120
121 #define CCK_DURATION_LIST(_short) \
122 CCK_ACK_DURATION(10, _short), \
123 CCK_ACK_DURATION(20, _short), \
124 CCK_ACK_DURATION(55, _short), \
125 CCK_ACK_DURATION(110, _short)
126
127 #define CCK_GROUP \
128 [MINSTREL_CCK_GROUP] = { \
129 .streams = 0, \
130 .flags = 0, \
131 .duration = { \
132 CCK_DURATION_LIST(false), \
133 CCK_DURATION_LIST(true) \
134 } \
135 }
136
137 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
138 static bool minstrel_vht_only = true;
139 module_param(minstrel_vht_only, bool, 0644);
140 MODULE_PARM_DESC(minstrel_vht_only,
141 "Use only VHT rates when VHT is supported by sta.");
142 #endif
143
144 /*
145 * To enable sufficiently targeted rate sampling, MCS rates are divided into
146 * groups, based on the number of streams and flags (HT40, SGI) that they
147 * use.
148 *
149 * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
150 * BW -> SGI -> #streams
151 */
152 const struct mcs_group minstrel_mcs_groups[] = {
153 MCS_GROUP(1, 0, BW_20),
154 MCS_GROUP(2, 0, BW_20),
155 #if MINSTREL_MAX_STREAMS >= 3
156 MCS_GROUP(3, 0, BW_20),
157 #endif
158
159 MCS_GROUP(1, 1, BW_20),
160 MCS_GROUP(2, 1, BW_20),
161 #if MINSTREL_MAX_STREAMS >= 3
162 MCS_GROUP(3, 1, BW_20),
163 #endif
164
165 MCS_GROUP(1, 0, BW_40),
166 MCS_GROUP(2, 0, BW_40),
167 #if MINSTREL_MAX_STREAMS >= 3
168 MCS_GROUP(3, 0, BW_40),
169 #endif
170
171 MCS_GROUP(1, 1, BW_40),
172 MCS_GROUP(2, 1, BW_40),
173 #if MINSTREL_MAX_STREAMS >= 3
174 MCS_GROUP(3, 1, BW_40),
175 #endif
176
177 CCK_GROUP,
178
179 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
180 VHT_GROUP(1, 0, BW_20),
181 VHT_GROUP(2, 0, BW_20),
182 #if MINSTREL_MAX_STREAMS >= 3
183 VHT_GROUP(3, 0, BW_20),
184 #endif
185
186 VHT_GROUP(1, 1, BW_20),
187 VHT_GROUP(2, 1, BW_20),
188 #if MINSTREL_MAX_STREAMS >= 3
189 VHT_GROUP(3, 1, BW_20),
190 #endif
191
192 VHT_GROUP(1, 0, BW_40),
193 VHT_GROUP(2, 0, BW_40),
194 #if MINSTREL_MAX_STREAMS >= 3
195 VHT_GROUP(3, 0, BW_40),
196 #endif
197
198 VHT_GROUP(1, 1, BW_40),
199 VHT_GROUP(2, 1, BW_40),
200 #if MINSTREL_MAX_STREAMS >= 3
201 VHT_GROUP(3, 1, BW_40),
202 #endif
203
204 VHT_GROUP(1, 0, BW_80),
205 VHT_GROUP(2, 0, BW_80),
206 #if MINSTREL_MAX_STREAMS >= 3
207 VHT_GROUP(3, 0, BW_80),
208 #endif
209
210 VHT_GROUP(1, 1, BW_80),
211 VHT_GROUP(2, 1, BW_80),
212 #if MINSTREL_MAX_STREAMS >= 3
213 VHT_GROUP(3, 1, BW_80),
214 #endif
215 #endif
216 };
217
218 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
219
220 static void
221 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
222
223 /*
224 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer)
225 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1
226 *
227 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported
228 */
229 static u16
230 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map)
231 {
232 u16 mask = 0;
233
234 if (bw == BW_20) {
235 if (nss != 3 && nss != 6)
236 mask = BIT(9);
237 } else if (bw == BW_80) {
238 if (nss == 3 || nss == 7)
239 mask = BIT(6);
240 else if (nss == 6)
241 mask = BIT(9);
242 } else {
243 WARN_ON(bw != BW_40);
244 }
245
246 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) {
247 case IEEE80211_VHT_MCS_SUPPORT_0_7:
248 mask |= 0x300;
249 break;
250 case IEEE80211_VHT_MCS_SUPPORT_0_8:
251 mask |= 0x200;
252 break;
253 case IEEE80211_VHT_MCS_SUPPORT_0_9:
254 break;
255 default:
256 mask = 0x3ff;
257 }
258
259 return 0x3ff & ~mask;
260 }
261
262 /*
263 * Look up an MCS group index based on mac80211 rate information
264 */
265 static int
266 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
267 {
268 return GROUP_IDX((rate->idx / 8) + 1,
269 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
270 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
271 }
272
273 static int
274 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate)
275 {
276 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate),
277 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
278 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
279 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH));
280 }
281
282 static struct minstrel_rate_stats *
283 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
284 struct ieee80211_tx_rate *rate)
285 {
286 int group, idx;
287
288 if (rate->flags & IEEE80211_TX_RC_MCS) {
289 group = minstrel_ht_get_group_idx(rate);
290 idx = rate->idx % 8;
291 } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
292 group = minstrel_vht_get_group_idx(rate);
293 idx = ieee80211_rate_get_vht_mcs(rate);
294 } else {
295 group = MINSTREL_CCK_GROUP;
296
297 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++)
298 if (rate->idx == mp->cck_rates[idx])
299 break;
300
301 /* short preamble */
302 if (!(mi->groups[group].supported & BIT(idx)))
303 idx += 4;
304 }
305 return &mi->groups[group].rates[idx];
306 }
307
308 static inline struct minstrel_rate_stats *
309 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
310 {
311 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
312 }
313
314
315 /*
316 * Recalculate success probabilities and counters for a rate using EWMA
317 */
318 static void
319 minstrel_calc_rate_ewma(struct minstrel_rate_stats *mr)
320 {
321 if (unlikely(mr->attempts > 0)) {
322 mr->sample_skipped = 0;
323 mr->cur_prob = MINSTREL_FRAC(mr->success, mr->attempts);
324 if (!mr->att_hist)
325 mr->probability = mr->cur_prob;
326 else
327 mr->probability = minstrel_ewma(mr->probability,
328 mr->cur_prob, EWMA_LEVEL);
329 mr->att_hist += mr->attempts;
330 mr->succ_hist += mr->success;
331 } else {
332 mr->sample_skipped++;
333 }
334 mr->last_success = mr->success;
335 mr->last_attempts = mr->attempts;
336 mr->success = 0;
337 mr->attempts = 0;
338 }
339
340 /*
341 * Calculate throughput based on the average A-MPDU length, taking into account
342 * the expected number of retransmissions and their expected length
343 */
344 static void
345 minstrel_ht_calc_tp(struct minstrel_ht_sta *mi, int group, int rate)
346 {
347 struct minstrel_rate_stats *mr;
348 unsigned int nsecs = 0;
349 unsigned int tp;
350 unsigned int prob;
351
352 mr = &mi->groups[group].rates[rate];
353 prob = mr->probability;
354
355 if (prob < MINSTREL_FRAC(1, 10)) {
356 mr->cur_tp = 0;
357 return;
358 }
359
360 /*
361 * For the throughput calculation, limit the probability value to 90% to
362 * account for collision related packet error rate fluctuation
363 */
364 if (prob > MINSTREL_FRAC(9, 10))
365 prob = MINSTREL_FRAC(9, 10);
366
367 if (group != MINSTREL_CCK_GROUP)
368 nsecs = 1000 * mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
369
370 nsecs += minstrel_mcs_groups[group].duration[rate];
371
372 /* prob is scaled - see MINSTREL_FRAC above */
373 tp = 1000000 * ((prob * 1000) / nsecs);
374 mr->cur_tp = MINSTREL_TRUNC(tp);
375 }
376
377 /*
378 * Find & sort topmost throughput rates
379 *
380 * If multiple rates provide equal throughput the sorting is based on their
381 * current success probability. Higher success probability is preferred among
382 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
383 */
384 static void
385 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
386 u16 *tp_list)
387 {
388 int cur_group, cur_idx, cur_thr, cur_prob;
389 int tmp_group, tmp_idx, tmp_thr, tmp_prob;
390 int j = MAX_THR_RATES;
391
392 cur_group = index / MCS_GROUP_RATES;
393 cur_idx = index % MCS_GROUP_RATES;
394 cur_thr = mi->groups[cur_group].rates[cur_idx].cur_tp;
395 cur_prob = mi->groups[cur_group].rates[cur_idx].probability;
396
397 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
398 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
399 tmp_thr = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
400 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].probability;
401
402 while (j > 0 && (cur_thr > tmp_thr ||
403 (cur_thr == tmp_thr && cur_prob > tmp_prob))) {
404 j--;
405 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
406 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
407 tmp_thr = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
408 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].probability;
409 }
410
411 if (j < MAX_THR_RATES - 1) {
412 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
413 (MAX_THR_RATES - (j + 1))));
414 }
415 if (j < MAX_THR_RATES)
416 tp_list[j] = index;
417 }
418
419 /*
420 * Find and set the topmost probability rate per sta and per group
421 */
422 static void
423 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index)
424 {
425 struct minstrel_mcs_group_data *mg;
426 struct minstrel_rate_stats *mr;
427 int tmp_group, tmp_idx, tmp_tp, tmp_prob, max_tp_group;
428
429 mg = &mi->groups[index / MCS_GROUP_RATES];
430 mr = &mg->rates[index % MCS_GROUP_RATES];
431
432 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES;
433 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES;
434 tmp_tp = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
435 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].probability;
436
437 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
438 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
439 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES;
440 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) &&
441 (max_tp_group != MINSTREL_CCK_GROUP))
442 return;
443
444 if (mr->probability > MINSTREL_FRAC(75, 100)) {
445 if (mr->cur_tp > tmp_tp)
446 mi->max_prob_rate = index;
447 if (mr->cur_tp > mg->rates[mg->max_group_prob_rate].cur_tp)
448 mg->max_group_prob_rate = index;
449 } else {
450 if (mr->probability > tmp_prob)
451 mi->max_prob_rate = index;
452 if (mr->probability > mg->rates[mg->max_group_prob_rate].probability)
453 mg->max_group_prob_rate = index;
454 }
455 }
456
457
458 /*
459 * Assign new rate set per sta and use CCK rates only if the fastest
460 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
461 * rate sets where MCS and CCK rates are mixed, because CCK rates can
462 * not use aggregation.
463 */
464 static void
465 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
466 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
467 u16 tmp_cck_tp_rate[MAX_THR_RATES])
468 {
469 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp;
470 int i;
471
472 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES;
473 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES;
474 tmp_cck_tp = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
475
476 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES;
477 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES;
478 tmp_mcs_tp = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
479
480 if (tmp_cck_tp > tmp_mcs_tp) {
481 for(i = 0; i < MAX_THR_RATES; i++) {
482 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i],
483 tmp_mcs_tp_rate);
484 }
485 }
486
487 }
488
489 /*
490 * Try to increase robustness of max_prob rate by decrease number of
491 * streams if possible.
492 */
493 static inline void
494 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
495 {
496 struct minstrel_mcs_group_data *mg;
497 struct minstrel_rate_stats *mr;
498 int tmp_max_streams, group;
499 int tmp_tp = 0;
500
501 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
502 MCS_GROUP_RATES].streams;
503 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
504 mg = &mi->groups[group];
505 if (!mg->supported || group == MINSTREL_CCK_GROUP)
506 continue;
507 mr = minstrel_get_ratestats(mi, mg->max_group_prob_rate);
508 if (tmp_tp < mr->cur_tp &&
509 (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
510 mi->max_prob_rate = mg->max_group_prob_rate;
511 tmp_tp = mr->cur_tp;
512 }
513 }
514 }
515
516 /*
517 * Update rate statistics and select new primary rates
518 *
519 * Rules for rate selection:
520 * - max_prob_rate must use only one stream, as a tradeoff between delivery
521 * probability and throughput during strong fluctuations
522 * - as long as the max prob rate has a probability of more than 75%, pick
523 * higher throughput rates, even if the probablity is a bit lower
524 */
525 static void
526 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
527 {
528 struct minstrel_mcs_group_data *mg;
529 struct minstrel_rate_stats *mr;
530 int group, i, j;
531 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
532 u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
533
534 if (mi->ampdu_packets > 0) {
535 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
536 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL);
537 mi->ampdu_len = 0;
538 mi->ampdu_packets = 0;
539 }
540
541 mi->sample_slow = 0;
542 mi->sample_count = 0;
543
544 /* Initialize global rate indexes */
545 for(j = 0; j < MAX_THR_RATES; j++){
546 tmp_mcs_tp_rate[j] = 0;
547 tmp_cck_tp_rate[j] = 0;
548 }
549
550 /* Find best rate sets within all MCS groups*/
551 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
552
553 mg = &mi->groups[group];
554 if (!mg->supported)
555 continue;
556
557 mi->sample_count++;
558
559 /* (re)Initialize group rate indexes */
560 for(j = 0; j < MAX_THR_RATES; j++)
561 tmp_group_tp_rate[j] = group;
562
563 for (i = 0; i < MCS_GROUP_RATES; i++) {
564 if (!(mg->supported & BIT(i)))
565 continue;
566
567 index = MCS_GROUP_RATES * group + i;
568
569 mr = &mg->rates[i];
570 mr->retry_updated = false;
571 minstrel_calc_rate_ewma(mr);
572 minstrel_ht_calc_tp(mi, group, i);
573
574 if (!mr->cur_tp)
575 continue;
576
577 /* Find max throughput rate set */
578 if (group != MINSTREL_CCK_GROUP) {
579 minstrel_ht_sort_best_tp_rates(mi, index,
580 tmp_mcs_tp_rate);
581 } else if (group == MINSTREL_CCK_GROUP) {
582 minstrel_ht_sort_best_tp_rates(mi, index,
583 tmp_cck_tp_rate);
584 }
585
586 /* Find max throughput rate set within a group */
587 minstrel_ht_sort_best_tp_rates(mi, index,
588 tmp_group_tp_rate);
589
590 /* Find max probability rate per group and global */
591 minstrel_ht_set_best_prob_rate(mi, index);
592 }
593
594 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
595 sizeof(mg->max_group_tp_rate));
596 }
597
598 /* Assign new rate set per sta */
599 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate);
600 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
601
602 /* Try to increase robustness of max_prob_rate*/
603 minstrel_ht_prob_rate_reduce_streams(mi);
604
605 /* try to sample all available rates during each interval */
606 mi->sample_count *= 8;
607
608 #ifdef CONFIG_MAC80211_DEBUGFS
609 /* use fixed index if set */
610 if (mp->fixed_rate_idx != -1) {
611 for (i = 0; i < 4; i++)
612 mi->max_tp_rate[i] = mp->fixed_rate_idx;
613 mi->max_prob_rate = mp->fixed_rate_idx;
614 }
615 #endif
616
617 /* Reset update timer */
618 mi->stats_update = jiffies;
619 }
620
621 static bool
622 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate)
623 {
624 if (rate->idx < 0)
625 return false;
626
627 if (!rate->count)
628 return false;
629
630 if (rate->flags & IEEE80211_TX_RC_MCS ||
631 rate->flags & IEEE80211_TX_RC_VHT_MCS)
632 return true;
633
634 return rate->idx == mp->cck_rates[0] ||
635 rate->idx == mp->cck_rates[1] ||
636 rate->idx == mp->cck_rates[2] ||
637 rate->idx == mp->cck_rates[3];
638 }
639
640 static void
641 minstrel_next_sample_idx(struct minstrel_ht_sta *mi)
642 {
643 struct minstrel_mcs_group_data *mg;
644
645 for (;;) {
646 mi->sample_group++;
647 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
648 mg = &mi->groups[mi->sample_group];
649
650 if (!mg->supported)
651 continue;
652
653 if (++mg->index >= MCS_GROUP_RATES) {
654 mg->index = 0;
655 if (++mg->column >= ARRAY_SIZE(sample_table))
656 mg->column = 0;
657 }
658 break;
659 }
660 }
661
662 static void
663 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
664 {
665 int group, orig_group;
666
667 orig_group = group = *idx / MCS_GROUP_RATES;
668 while (group > 0) {
669 group--;
670
671 if (!mi->groups[group].supported)
672 continue;
673
674 if (minstrel_mcs_groups[group].streams >
675 minstrel_mcs_groups[orig_group].streams)
676 continue;
677
678 if (primary)
679 *idx = mi->groups[group].max_group_tp_rate[0];
680 else
681 *idx = mi->groups[group].max_group_tp_rate[1];
682 break;
683 }
684 }
685
686 static void
687 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
688 {
689 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
690 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
691 u16 tid;
692
693 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
694 return;
695
696 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
697 return;
698
699 tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
700 if (likely(sta->ampdu_mlme.tid_tx[tid]))
701 return;
702
703 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
704 return;
705
706 ieee80211_start_tx_ba_session(pubsta, tid, 5000);
707 }
708
709 static void
710 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
711 struct ieee80211_sta *sta, void *priv_sta,
712 struct sk_buff *skb)
713 {
714 struct minstrel_ht_sta_priv *msp = priv_sta;
715 struct minstrel_ht_sta *mi = &msp->ht;
716 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
717 struct ieee80211_tx_rate *ar = info->status.rates;
718 struct minstrel_rate_stats *rate, *rate2;
719 struct minstrel_priv *mp = priv;
720 bool last, update = false;
721 int i;
722
723 if (!msp->is_ht)
724 return mac80211_minstrel.tx_status(priv, sband, sta, &msp->legacy, skb);
725
726 /* This packet was aggregated but doesn't carry status info */
727 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
728 !(info->flags & IEEE80211_TX_STAT_AMPDU))
729 return;
730
731 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
732 info->status.ampdu_ack_len =
733 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
734 info->status.ampdu_len = 1;
735 }
736
737 mi->ampdu_packets++;
738 mi->ampdu_len += info->status.ampdu_len;
739
740 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
741 mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len);
742 mi->sample_tries = 1;
743 mi->sample_count--;
744 }
745
746 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
747 mi->sample_packets += info->status.ampdu_len;
748
749 last = !minstrel_ht_txstat_valid(mp, &ar[0]);
750 for (i = 0; !last; i++) {
751 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
752 !minstrel_ht_txstat_valid(mp, &ar[i + 1]);
753
754 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
755
756 if (last)
757 rate->success += info->status.ampdu_ack_len;
758
759 rate->attempts += ar[i].count * info->status.ampdu_len;
760 }
761
762 /*
763 * check for sudden death of spatial multiplexing,
764 * downgrade to a lower number of streams if necessary.
765 */
766 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
767 if (rate->attempts > 30 &&
768 MINSTREL_FRAC(rate->success, rate->attempts) <
769 MINSTREL_FRAC(20, 100)) {
770 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
771 update = true;
772 }
773
774 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
775 if (rate2->attempts > 30 &&
776 MINSTREL_FRAC(rate2->success, rate2->attempts) <
777 MINSTREL_FRAC(20, 100)) {
778 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
779 update = true;
780 }
781
782 if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000)) {
783 update = true;
784 minstrel_ht_update_stats(mp, mi);
785 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
786 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
787 minstrel_aggr_check(sta, skb);
788 }
789
790 if (update)
791 minstrel_ht_update_rates(mp, mi);
792 }
793
794 static void
795 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
796 int index)
797 {
798 struct minstrel_rate_stats *mr;
799 const struct mcs_group *group;
800 unsigned int tx_time, tx_time_rtscts, tx_time_data;
801 unsigned int cw = mp->cw_min;
802 unsigned int ctime = 0;
803 unsigned int t_slot = 9; /* FIXME */
804 unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
805 unsigned int overhead = 0, overhead_rtscts = 0;
806
807 mr = minstrel_get_ratestats(mi, index);
808 if (mr->probability < MINSTREL_FRAC(1, 10)) {
809 mr->retry_count = 1;
810 mr->retry_count_rtscts = 1;
811 return;
812 }
813
814 mr->retry_count = 2;
815 mr->retry_count_rtscts = 2;
816 mr->retry_updated = true;
817
818 group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
819 tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len / 1000;
820
821 /* Contention time for first 2 tries */
822 ctime = (t_slot * cw) >> 1;
823 cw = min((cw << 1) | 1, mp->cw_max);
824 ctime += (t_slot * cw) >> 1;
825 cw = min((cw << 1) | 1, mp->cw_max);
826
827 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) {
828 overhead = mi->overhead;
829 overhead_rtscts = mi->overhead_rtscts;
830 }
831
832 /* Total TX time for data and Contention after first 2 tries */
833 tx_time = ctime + 2 * (overhead + tx_time_data);
834 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
835
836 /* See how many more tries we can fit inside segment size */
837 do {
838 /* Contention time for this try */
839 ctime = (t_slot * cw) >> 1;
840 cw = min((cw << 1) | 1, mp->cw_max);
841
842 /* Total TX time after this try */
843 tx_time += ctime + overhead + tx_time_data;
844 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
845
846 if (tx_time_rtscts < mp->segment_size)
847 mr->retry_count_rtscts++;
848 } while ((tx_time < mp->segment_size) &&
849 (++mr->retry_count < mp->max_retry));
850 }
851
852
853 static void
854 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
855 struct ieee80211_sta_rates *ratetbl, int offset, int index)
856 {
857 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
858 struct minstrel_rate_stats *mr;
859 u8 idx;
860 u16 flags = group->flags;
861
862 mr = minstrel_get_ratestats(mi, index);
863 if (!mr->retry_updated)
864 minstrel_calc_retransmit(mp, mi, index);
865
866 if (mr->probability < MINSTREL_FRAC(20, 100) || !mr->retry_count) {
867 ratetbl->rate[offset].count = 2;
868 ratetbl->rate[offset].count_rts = 2;
869 ratetbl->rate[offset].count_cts = 2;
870 } else {
871 ratetbl->rate[offset].count = mr->retry_count;
872 ratetbl->rate[offset].count_cts = mr->retry_count;
873 ratetbl->rate[offset].count_rts = mr->retry_count_rtscts;
874 }
875
876 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP)
877 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
878 else if (flags & IEEE80211_TX_RC_VHT_MCS)
879 idx = ((group->streams - 1) << 4) |
880 ((index % MCS_GROUP_RATES) & 0xF);
881 else
882 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8;
883
884 if (offset > 0) {
885 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
886 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
887 }
888
889 ratetbl->rate[offset].idx = idx;
890 ratetbl->rate[offset].flags = flags;
891 }
892
893 static void
894 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
895 {
896 struct ieee80211_sta_rates *rates;
897 int i = 0;
898
899 rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
900 if (!rates)
901 return;
902
903 /* Start with max_tp_rate[0] */
904 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
905
906 if (mp->hw->max_rates >= 3) {
907 /* At least 3 tx rates supported, use max_tp_rate[1] next */
908 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
909 }
910
911 if (mp->hw->max_rates >= 2) {
912 /*
913 * At least 2 tx rates supported, use max_prob_rate next */
914 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
915 }
916
917 rates->rate[i].idx = -1;
918 rate_control_set_rates(mp->hw, mi->sta, rates);
919 }
920
921 static inline int
922 minstrel_get_duration(int index)
923 {
924 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
925 return group->duration[index % MCS_GROUP_RATES];
926 }
927
928 static int
929 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
930 {
931 struct minstrel_rate_stats *mr;
932 struct minstrel_mcs_group_data *mg;
933 unsigned int sample_dur, sample_group, cur_max_tp_streams;
934 int sample_idx = 0;
935
936 if (mi->sample_wait > 0) {
937 mi->sample_wait--;
938 return -1;
939 }
940
941 if (!mi->sample_tries)
942 return -1;
943
944 sample_group = mi->sample_group;
945 mg = &mi->groups[sample_group];
946 sample_idx = sample_table[mg->column][mg->index];
947 minstrel_next_sample_idx(mi);
948
949 if (!(mg->supported & BIT(sample_idx)))
950 return -1;
951
952 mr = &mg->rates[sample_idx];
953 sample_idx += sample_group * MCS_GROUP_RATES;
954
955 /*
956 * Sampling might add some overhead (RTS, no aggregation)
957 * to the frame. Hence, don't use sampling for the currently
958 * used rates.
959 */
960 if (sample_idx == mi->max_tp_rate[0] ||
961 sample_idx == mi->max_tp_rate[1] ||
962 sample_idx == mi->max_prob_rate)
963 return -1;
964
965 /*
966 * Do not sample if the probability is already higher than 95%
967 * to avoid wasting airtime.
968 */
969 if (mr->probability > MINSTREL_FRAC(95, 100))
970 return -1;
971
972 /*
973 * Make sure that lower rates get sampled only occasionally,
974 * if the link is working perfectly.
975 */
976
977 cur_max_tp_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
978 MCS_GROUP_RATES].streams;
979 sample_dur = minstrel_get_duration(sample_idx);
980 if (sample_dur >= minstrel_get_duration(mi->max_tp_rate[1]) &&
981 (cur_max_tp_streams - 1 <
982 minstrel_mcs_groups[sample_group].streams ||
983 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
984 if (mr->sample_skipped < 20)
985 return -1;
986
987 if (mi->sample_slow++ > 2)
988 return -1;
989 }
990 mi->sample_tries--;
991
992 return sample_idx;
993 }
994
995 static void
996 minstrel_ht_check_cck_shortpreamble(struct minstrel_priv *mp,
997 struct minstrel_ht_sta *mi, bool val)
998 {
999 u8 supported = mi->groups[MINSTREL_CCK_GROUP].supported;
1000
1001 if (!supported || !mi->cck_supported_short)
1002 return;
1003
1004 if (supported & (mi->cck_supported_short << (val * 4)))
1005 return;
1006
1007 supported ^= mi->cck_supported_short | (mi->cck_supported_short << 4);
1008 mi->groups[MINSTREL_CCK_GROUP].supported = supported;
1009 }
1010
1011 static void
1012 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1013 struct ieee80211_tx_rate_control *txrc)
1014 {
1015 const struct mcs_group *sample_group;
1016 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1017 struct ieee80211_tx_rate *rate = &info->status.rates[0];
1018 struct minstrel_ht_sta_priv *msp = priv_sta;
1019 struct minstrel_ht_sta *mi = &msp->ht;
1020 struct minstrel_priv *mp = priv;
1021 int sample_idx;
1022
1023 if (rate_control_send_low(sta, priv_sta, txrc))
1024 return;
1025
1026 if (!msp->is_ht)
1027 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
1028
1029 info->flags |= mi->tx_flags;
1030 minstrel_ht_check_cck_shortpreamble(mp, mi, txrc->short_preamble);
1031
1032 #ifdef CONFIG_MAC80211_DEBUGFS
1033 if (mp->fixed_rate_idx != -1)
1034 return;
1035 #endif
1036
1037 /* Don't use EAPOL frames for sampling on non-mrr hw */
1038 if (mp->hw->max_rates == 1 &&
1039 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1040 sample_idx = -1;
1041 else
1042 sample_idx = minstrel_get_sample_rate(mp, mi);
1043
1044 mi->total_packets++;
1045
1046 /* wraparound */
1047 if (mi->total_packets == ~0) {
1048 mi->total_packets = 0;
1049 mi->sample_packets = 0;
1050 }
1051
1052 if (sample_idx < 0)
1053 return;
1054
1055 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
1056 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1057 rate->count = 1;
1058
1059 if (sample_idx / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) {
1060 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1061 rate->idx = mp->cck_rates[idx];
1062 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1063 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
1064 sample_group->streams);
1065 } else {
1066 rate->idx = sample_idx % MCS_GROUP_RATES +
1067 (sample_group->streams - 1) * 8;
1068 }
1069
1070 rate->flags = sample_group->flags;
1071 }
1072
1073 static void
1074 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1075 struct ieee80211_supported_band *sband,
1076 struct ieee80211_sta *sta)
1077 {
1078 int i;
1079
1080 if (sband->band != IEEE80211_BAND_2GHZ)
1081 return;
1082
1083 if (!(mp->hw->flags & IEEE80211_HW_SUPPORTS_HT_CCK_RATES))
1084 return;
1085
1086 mi->cck_supported = 0;
1087 mi->cck_supported_short = 0;
1088 for (i = 0; i < 4; i++) {
1089 if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
1090 continue;
1091
1092 mi->cck_supported |= BIT(i);
1093 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1094 mi->cck_supported_short |= BIT(i);
1095 }
1096
1097 mi->groups[MINSTREL_CCK_GROUP].supported = mi->cck_supported;
1098 }
1099
1100 static void
1101 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1102 struct cfg80211_chan_def *chandef,
1103 struct ieee80211_sta *sta, void *priv_sta)
1104 {
1105 struct minstrel_priv *mp = priv;
1106 struct minstrel_ht_sta_priv *msp = priv_sta;
1107 struct minstrel_ht_sta *mi = &msp->ht;
1108 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
1109 u16 sta_cap = sta->ht_cap.cap;
1110 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
1111 int use_vht;
1112 int n_supported = 0;
1113 int ack_dur;
1114 int stbc;
1115 int i;
1116
1117 /* fall back to the old minstrel for legacy stations */
1118 if (!sta->ht_cap.ht_supported)
1119 goto use_legacy;
1120
1121 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1122
1123 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
1124 if (vht_cap->vht_supported)
1125 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1126 else
1127 #endif
1128 use_vht = 0;
1129
1130 msp->is_ht = true;
1131 memset(mi, 0, sizeof(*mi));
1132
1133 mi->sta = sta;
1134 mi->stats_update = jiffies;
1135
1136 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1137 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1138 mi->overhead += ack_dur;
1139 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1140
1141 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1142
1143 /* When using MRR, sample more on the first attempt, without delay */
1144 if (mp->has_mrr) {
1145 mi->sample_count = 16;
1146 mi->sample_wait = 0;
1147 } else {
1148 mi->sample_count = 8;
1149 mi->sample_wait = 8;
1150 }
1151 mi->sample_tries = 4;
1152
1153 /* TODO tx_flags for vht - ATM the RC API is not fine-grained enough */
1154 if (!use_vht) {
1155 stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >>
1156 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1157 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1158
1159 if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING)
1160 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1161 }
1162
1163 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1164 u32 gflags = minstrel_mcs_groups[i].flags;
1165 int bw, nss;
1166
1167 mi->groups[i].supported = 0;
1168 if (i == MINSTREL_CCK_GROUP) {
1169 minstrel_ht_update_cck(mp, mi, sband, sta);
1170 continue;
1171 }
1172
1173 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1174 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1175 if (!(sta_cap & IEEE80211_HT_CAP_SGI_40))
1176 continue;
1177 } else {
1178 if (!(sta_cap & IEEE80211_HT_CAP_SGI_20))
1179 continue;
1180 }
1181 }
1182
1183 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1184 sta->bandwidth < IEEE80211_STA_RX_BW_40)
1185 continue;
1186
1187 nss = minstrel_mcs_groups[i].streams;
1188
1189 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1190 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1191 continue;
1192
1193 /* HT rate */
1194 if (gflags & IEEE80211_TX_RC_MCS) {
1195 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
1196 if (use_vht && minstrel_vht_only)
1197 continue;
1198 #endif
1199 mi->groups[i].supported = mcs->rx_mask[nss - 1];
1200 if (mi->groups[i].supported)
1201 n_supported++;
1202 continue;
1203 }
1204
1205 /* VHT rate */
1206 if (!vht_cap->vht_supported ||
1207 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1208 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1209 continue;
1210
1211 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1212 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 ||
1213 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1214 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1215 continue;
1216 }
1217 }
1218
1219 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1220 bw = BW_40;
1221 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1222 bw = BW_80;
1223 else
1224 bw = BW_20;
1225
1226 mi->groups[i].supported = minstrel_get_valid_vht_rates(bw, nss,
1227 vht_cap->vht_mcs.tx_mcs_map);
1228
1229 if (mi->groups[i].supported)
1230 n_supported++;
1231 }
1232
1233 if (!n_supported)
1234 goto use_legacy;
1235
1236 /* create an initial rate table with the lowest supported rates */
1237 minstrel_ht_update_stats(mp, mi);
1238 minstrel_ht_update_rates(mp, mi);
1239
1240 return;
1241
1242 use_legacy:
1243 msp->is_ht = false;
1244 memset(&msp->legacy, 0, sizeof(msp->legacy));
1245 msp->legacy.r = msp->ratelist;
1246 msp->legacy.sample_table = msp->sample_table;
1247 return mac80211_minstrel.rate_init(priv, sband, chandef, sta,
1248 &msp->legacy);
1249 }
1250
1251 static void
1252 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1253 struct cfg80211_chan_def *chandef,
1254 struct ieee80211_sta *sta, void *priv_sta)
1255 {
1256 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1257 }
1258
1259 static void
1260 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1261 struct cfg80211_chan_def *chandef,
1262 struct ieee80211_sta *sta, void *priv_sta,
1263 u32 changed)
1264 {
1265 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1266 }
1267
1268 static void *
1269 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1270 {
1271 struct ieee80211_supported_band *sband;
1272 struct minstrel_ht_sta_priv *msp;
1273 struct minstrel_priv *mp = priv;
1274 struct ieee80211_hw *hw = mp->hw;
1275 int max_rates = 0;
1276 int i;
1277
1278 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
1279 sband = hw->wiphy->bands[i];
1280 if (sband && sband->n_bitrates > max_rates)
1281 max_rates = sband->n_bitrates;
1282 }
1283
1284 msp = kzalloc(sizeof(*msp), gfp);
1285 if (!msp)
1286 return NULL;
1287
1288 msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
1289 if (!msp->ratelist)
1290 goto error;
1291
1292 msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
1293 if (!msp->sample_table)
1294 goto error1;
1295
1296 return msp;
1297
1298 error1:
1299 kfree(msp->ratelist);
1300 error:
1301 kfree(msp);
1302 return NULL;
1303 }
1304
1305 static void
1306 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1307 {
1308 struct minstrel_ht_sta_priv *msp = priv_sta;
1309
1310 kfree(msp->sample_table);
1311 kfree(msp->ratelist);
1312 kfree(msp);
1313 }
1314
1315 static void *
1316 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
1317 {
1318 return mac80211_minstrel.alloc(hw, debugfsdir);
1319 }
1320
1321 static void
1322 minstrel_ht_free(void *priv)
1323 {
1324 mac80211_minstrel.free(priv);
1325 }
1326
1327 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1328 {
1329 struct minstrel_ht_sta_priv *msp = priv_sta;
1330 struct minstrel_ht_sta *mi = &msp->ht;
1331 int i, j;
1332
1333 if (!msp->is_ht)
1334 return mac80211_minstrel.get_expected_throughput(priv_sta);
1335
1336 i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
1337 j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
1338
1339 /* convert cur_tp from pkt per second in kbps */
1340 return mi->groups[i].rates[j].cur_tp * AVG_PKT_SIZE * 8 / 1024;
1341 }
1342
1343 static const struct rate_control_ops mac80211_minstrel_ht = {
1344 .name = "minstrel_ht",
1345 .tx_status = minstrel_ht_tx_status,
1346 .get_rate = minstrel_ht_get_rate,
1347 .rate_init = minstrel_ht_rate_init,
1348 .rate_update = minstrel_ht_rate_update,
1349 .alloc_sta = minstrel_ht_alloc_sta,
1350 .free_sta = minstrel_ht_free_sta,
1351 .alloc = minstrel_ht_alloc,
1352 .free = minstrel_ht_free,
1353 #ifdef CONFIG_MAC80211_DEBUGFS
1354 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
1355 .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
1356 #endif
1357 .get_expected_throughput = minstrel_ht_get_expected_throughput,
1358 };
1359
1360
1361 static void __init init_sample_table(void)
1362 {
1363 int col, i, new_idx;
1364 u8 rnd[MCS_GROUP_RATES];
1365
1366 memset(sample_table, 0xff, sizeof(sample_table));
1367 for (col = 0; col < SAMPLE_COLUMNS; col++) {
1368 prandom_bytes(rnd, sizeof(rnd));
1369 for (i = 0; i < MCS_GROUP_RATES; i++) {
1370 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
1371 while (sample_table[col][new_idx] != 0xff)
1372 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1373
1374 sample_table[col][new_idx] = i;
1375 }
1376 }
1377 }
1378
1379 int __init
1380 rc80211_minstrel_ht_init(void)
1381 {
1382 init_sample_table();
1383 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1384 }
1385
1386 void
1387 rc80211_minstrel_ht_exit(void)
1388 {
1389 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
1390 }
Linux kernel - Deliverables
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